/*
 *  Date: 2011-11-7 下午06:21:15
 *  Copyright (c) 2011 asiainfo-linkage
 */
package com.gjframe.example.utils;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.gjframe.commen.helper.StringUtils;

public class CookieUtils {

    /**
     * 每页条数cookie名称
     */
    public static final String COOKIE_PAGE_SIZE = "_cookie_page_size";

    /**
     * 默认每页条数
     */
    public static final int DEFAULT_SIZE = 20;

    /**
     * 最大每页条数
     */
    public static final int MAX_SIZE = 200;

    /**
     * 获得cookie的每页条数
     * 
     * 使用_cookie_page_size作为cookie name
     * 
     * @param request
     *            HttpServletRequest
     * @return default:20 max:200
     */
    public static int getPageSize(HttpServletRequest request) {
        Cookie cookie = getCookie(request, COOKIE_PAGE_SIZE);
        int count = 0;
        if (cookie != null) {
            try {
                count = Integer.parseInt(cookie.getValue());
            } catch (Exception e) {
            }
        }
        if (count <= 0) {
            count = DEFAULT_SIZE;
        } else if (count > MAX_SIZE) {
            count = MAX_SIZE;
        }
        return count;
    }

    /**
     * 获得cookie
     * 
     * @param request
     *            HttpServletRequest
     * @param name
     *            cookie name
     * @return if exist return cookie, else return null.
     */
    public static Cookie getCookie(HttpServletRequest request, String name) {
        Cookie[] cookies = request.getCookies();
        if (cookies != null && cookies.length > 0) {
            for (Cookie c : cookies) {
                if (c.getName().equals(name)) {
                    return c;
                }
            }
        }
        return null;
    }

    /**
     * 根据部署路径，将cookie保存在根目录。
     * 
     * @param request
     * @param response
     * @param name
     * @param value
     * @return
     */
    public static Cookie addCookie(HttpServletRequest request, HttpServletResponse response, String name, String value) {
        Cookie cookie = new Cookie(name, value);
        String ctx = request.getContextPath();
        if (StringUtils.isBlank(ctx)) {
            cookie.setPath("/");
        } else {
            // @TODO ctx后是否要加'/'，应该不要？
            cookie.setPath(ctx);
        }
        response.addCookie(cookie);
        return cookie;

    }

    /**
     * 取消cookie
     * 
     * @param response
     * @param name
     * @param domain
     */
    public static void cancleCookie(HttpServletResponse response, String name, String domain) {
        Cookie cookie = new Cookie(name, null);
        cookie.setMaxAge(0);
        cookie.setPath("/");
        if (!StringUtils.isBlank(domain)) {
            cookie.setDomain(domain);
        }
        response.addCookie(cookie);
    }

}
